                             :pressure               [:psi :kPa]
                             :proppant-concentration [:lb-per-gal :lb/gal :kg-per-m3 :kg/m3]
                             :slurry-rate            [:bbl-per-min :bpm :m3-per-min :m3/min]
-                            :volume                 [:bbl :m3]}]
+                            :volume                 [:bbl :m3]
+                            :temperature            [:F :C]}]
     (fn [] (rand-nth (get quantity-units-map physical-quantity)))))
 
 (def rand-density-unit (rand-unit :density))

(def rand-pressure-unit (rand-unit :pressure))
(def rand-proppant-concentration-unit (rand-unit :proppant-concentration))
(def rand-slurry-rate-unit (rand-unit :slurry-rate))
(def rand-volume-unit (rand-unit :volume))

(defn convert-units-f [from to]
  (let [factors   {[:m :ft]                   3.28084
                   [:kg :lb]                  2.20462262185
                   [:m3 :bbl]                 6.28981077
                   [:psi :kPa]                6.894757293168361
                   [:lb-per-gal :kg-per-m3]   119.826
                   [:lb-per-cu-ft :kg-per-m3] 16.0185}
        converter {[:ft :m]                   #(/ % (factors [:m :ft]))
                   [:m :ft]                   #(* % (factors [:m :ft]))
                   [:lb :kg]                  #(/ % (factors [:kg :lb]))
                   [:kg :lb]                  #(* % (factors [:kg :lb]))
                   [:bbl :m3]                 #(/ % (factors [:m3 :bbl]))
                   [:m3 :bbl]                 #(* % (factors [:m3 :bbl]))
                   [:psi :kPa]                #(* % (factors [:psi :kPa]))
                   [:kPa :psi]                #(/ % (factors [:psi :kPa]))
                   [:lb-per-gal :kg-per-m3]   #(* % (factors [:lb-per-gal :kg-per-m3]))
                   [:kg-per-m3 :lb-per-gal]   #(/ % (factors [:lb-per-gal :kg-per-m3]))
                   [:m3-per-min :bbl-per-min] #(* % (factors [:m3 :bbl]))
                   [:bbl-per-min :m3-per-min] #(/ % (factors [:lb-per-gal :kg-per-m3]))
                   [:lb-per-cu-ft :kg-per-m3] #(* % (factors [:lb-per-cu-ft :kg-per-m3]))
                   [:kg-per-m3 :lb-per-cu-ft] #(/ % (factors [:lb-per-cu-ft :kg-per-m3]))
                   [:C :F]                    #(+ (* % 1.8) 32)}]
    (converter [from to])))

(defn typical-vertical-depth []

                          :pressure
                          :proppant-concentration
                          :slurry-rate
                          :temperature
                          :volume])

(defn rand-physical-quantity []
